The Astom Martin pads also fit the calipers as SiFab says give the right offset, thank you SiFab we are now sorted.
Mintex MGB 522 pads as fitted to Astom Martin/Volvo
You can see the material offset and the pads are larger.
DSC_0627 by
Robert & Ali Davies, on Flickr
DSC_0634 by
Robert & Ali Davies, on Flickr